Dark energy equation of state can be effectively described by that of a barotropic fluid. The
barotropic fluid model describes the background evolution and the functional form of the …

Braneworld models have been proposed as a possible solution to the problem of the
accelerated expansion of the Universe. The idea is to dispense the dark energy (DE) and …

The accelerated expansion of the universe is a rather established fact in cosmology and
many different models have been proposed as a viable explanation. Many of these models …

Quintessence can cluster only on horizon scales. What is the effect on the observed matter
distribution? To answer this, we need a relativistic approach that goes beyond the standard …

Recent results of Planck data reveal that the power [1, 2] in the low multipoles of the CMB
angular power spectrum, approximately up to l= 30, is significantly lower than the …

Observations have confirmed the accelerated expansion of the universe. The accelerated
expansion can be modelled by invoking a cosmological constant or a dynamical model of …

A non-canonical scalar tachyon field is a viable candidate for dark energy and has been
found to be in good agreement with observational data. Background data alone cannot …

We propose a model of the evolution of the tachyonic scalar field over two phases in the
universe. The field components do not interact in phase I, while in the subsequent phase II …

Dynamical models for dark energy are an alternative to the cosmological constant. It is
important to investigate properties of perturbations in these models and go beyond the …

Thus far, there does not appear to be an agreed (or adequate) definition of homogeneous
dark energy (DE). This paper seeks to define a valid, adequate homogeneity condition for …